摘要
目的测量并比较多曲方丝弓与镍钛方丝分别在各牙位间的局部载荷挠曲率,分析多曲方丝弓的力学特性。方法用0.016×0.022英寸的不锈钢方丝按 Kim 标准弯制 MEAW 弓丝中独立的"L"形曲。用 Instron 2343型电子万能材料力学试验机及 Series IX 软件在室温下对"L"形曲及0.016×0.022英寸 NiTi 平直方丝分别在上下颌各牙位间进行加载和卸载实验,测得各自的局部载荷挠曲率 SPSS11.0软件包进行统计分析。结果"L"形曲与 NiTi 方丝在各牙位间加载和卸载时,在牙位1-2和2-3,各"L"形曲的局部载荷挠曲率比 NiTi 方丝的大,而在后牙区各牙位间的各"L"形曲的局部载荷挠曲率比 NiTi 方丝的小,其差异有显著性(P<0.01)。结论 MEAW 的局部载荷挠曲率较之 NiTi 方丝,在前牙区更大,在后牙区更小,在牙位3-4和4-5下降得更多。
Objective The aim of this study was to compare the regional load deflection rate （LDR） between multiloop edgewise arch wire （MEAW） and nickel-titanium rectangular wire （NiTi） in individual interbracket span, to understand the mechanical properties of MEAW. Methods The stainless steel of.016×. 022-inch was bent with single L-loop of 5 different sizes as described by Kirn. The LDR of each L- loop at the individual interbracket span when loading and unloading was measured by using the Instron at a crosshead speed of 1 mm/min and maximum deflection of 1.0 turn at room temperature. Five specimens were tested under each experimental condition to eliminate the possibility of changes in the physical properties of the wires as a result of the stress from repeated measurements. The regional LDRs of NiTi wires were measured with the same methods. The data were analysed by SPSS11.0. Results Tested when loading and unloading, in the anterior segments, the regional LDRs of the L-loops were greater than those for NiTi wires. While for the posterior segments, the regional LDRs were greater for NiTi wires than those for L-loops（P〈0. 0l）. Conclusion Compared with the regional LDRs for NiTi wires, the value for MEAW arch wires are higher at anterior segments and lower at posterior segments, with remarkable decrease at regions between canine and premolars.
出处
《口腔正畸学》
2008年第3期100-103,共4页
Chinese Journal of Orthodontics
关键词
多曲方丝弓
镍钛方丝
载荷挠曲率
Multiloop edgewise arch wire
Nickel-titanium
Load deflection rate
